| /* Copyright (C) 1996-2016 Free Software Foundation, Inc. |
| Contributed by Richard Henderson (rth@tamu.edu) |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library. If not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| /* Copy no more than COUNT bytes of the null-terminated string from |
| SRC to DST. If SRC does not cover all of COUNT, the balance is |
| zeroed. */ |
| |
| #include <sysdep.h> |
| |
| .set noat |
| .set noreorder |
| |
| .text |
| |
| ENTRY(strncpy) |
| ldgp gp, 0(pv) |
| #ifdef PROF |
| lda AT, _mcount |
| jsr AT, (AT), _mcount |
| #endif |
| .prologue 1 |
| |
| mov a0, v0 # set return value now |
| beq a2, $zerocount |
| jsr t9, __stxncpy # do the work of the copy |
| |
| bne a2, $multiword # do we have full words left? |
| |
| .align 3 |
| subq t8, 1, t2 # e0 : guess not |
| subq t10, 1, t3 # .. e1 : |
| or t2, t8, t2 # e0 : clear the bits between the last |
| or t3, t10, t3 # .. e1 : written byte and the last byte in |
| andnot t3, t2, t3 # e0 : COUNT |
| zap t0, t3, t0 # e1 : |
| stq_u t0, 0(a0) # e0 : |
| ret # .. e1 : |
| |
| $multiword: |
| subq t8, 1, t7 # e0 : clear the final bits in the prev |
| or t7, t8, t7 # e1 : word |
| zapnot t0, t7, t0 # e0 : |
| subq a2, 1, a2 # .. e1 : |
| stq_u t0, 0(a0) # e0 : |
| addq a0, 8, a0 # .. e1 : |
| |
| beq a2, 1f # e1 : |
| blbc a2, 0f # e1 : |
| |
| stq_u zero, 0(a0) # e0 : zero one word |
| subq a2, 1, a2 # .. e1 : |
| addq a0, 8, a0 # e0 : |
| beq a2, 1f # .. e1 : |
| |
| 0: stq_u zero, 0(a0) # e0 : zero two words |
| subq a2, 2, a2 # .. e1 : |
| stq_u zero, 8(a0) # e0 : |
| addq a0, 16, a0 # .. e1 : |
| bne a2, 0b # e1 : |
| unop |
| |
| 1: ldq_u t0, 0(a0) # e0 : clear the leading bits in the final |
| subq t10, 1, t7 # .. e1 : word |
| or t7, t10, t7 # e0 : |
| zap t0, t7, t0 # e1 (stall) |
| stq_u t0, 0(a0) # e0 : |
| |
| $zerocount: |
| ret # .. e1 : |
| |
| END(strncpy) |
| libc_hidden_builtin_def (strncpy) |